Conveyor apparatus

ABSTRACT

A live roller zero pressure accumulation conveyor is described which includes a drive shaft and a plurality of axially aligned countershafts, each of which is driven by the drive shaft through a clutch for selective power transmission to individual groups of conveyor rollers associated therewith. Each group of rollers has, at its forward or downstream end, a trigger device which senses the presence of a conveyed article. These trigger devices operate to selectively engage and disengage the clutch associated therewith to achieve and maintain a desired spacing between articles being transported on the conveyor. Preferably, dual trigger devices are used in a manner which requires coincident actuation of both trigger devices before the clutch associated with a given group of rollers is disengaged.

United States Patent 1191 Malt etal.

1 1 CONVEYOR APPARATUS [75] inventors: Richard P. Molt, Olympia Fields;

Woodruff A. Morey, Flossmoor,

both of 111.

[73] Assignec: Ermanco Incorporated, Grand Haven, Mich. [22] Filed: July 24, 1972 [21] Appl. N0.: 274,795

[52] US. Cl. .i 198/127 R, 192/54 [51] Int. Cl. 865g 13/02 [58] Field of Search 198/127 R; 74/405 [56] References Cited UNITED STATES PATENTS 2,733,919 2/1956 Anderson 271/125 3,021,719 2/1962 Conrad 74/405 3,397,589 8/1968 Moore 74/405 3,590,456 7/1971 Seaman 74/243 R 3,643,788 2/1972 Werntz 198/127 R 3,696,912 10/1972 Fleischauer 198/127 R Oct. 8, 1974 Primary Examiner-Richard E. Aegerter Attorney, Agent, or FirmLockwood, Dewey, Zickert & Alex 5 7 ABSTRACT A live roller zero pressure accumulation conveyor is described which includes a drive shaft and a plurality of axially aligned countershafts, each of which is driven by the drive shaft through a clutch for selective 40 Claims, 24 Drawing Figures PAIENTED 001 81914 PATENTE'D UB7 81974 3,840,110 SHEET 20$ 8 PATENTED 81974 SHEEI308 3,840,110 I sum 70; a

PAIENTEDUBT 81974 CONVEYOR APPARATUS The present invention generally relates to live roller conveyors used to transport articles along a predetermined path and, in particular, is directed to improved drive constructions and article spacing control systems for live roller conveyors. In this regard, an important embodiment of the present invention is specifically directed to live roller zero pressure accumulation conveyors of the type wherein the conveyor rollers are each driven by individual endless belts, which conveyors are characterized by a number of novel advantageous features including greatly facilitated belt replacement and power transmitting clutches of improved design and construction.

Live roller conveyors, namely, conveyors wherein powered rollers from the conveying surface, are well known in the art. In general, conventional devices of this type employ various drive mechanisms which inelude, for example, systems wherein power is directly supplied to load supporting rollers by a chain and sprocket drive, systems wherein the rollers are powered by anendless belt running above or below rollers which are transversely aligned with respect to the direction of belt travel, and systems wherein each of the rollers forming rhe conveying surface are directly connected to a powered drive shaft by individual endless belts.

Live roller conveyors of the general type described above are often provided with control systems which permit accumulation of articles being conveyedand regulate the spacing between articles being conveyed thereon. in this regard, the term live roller accumulation conveyor is generally used to designate conveyors in which the flow of packages being carried by the conveyor may be brought to a stop at a downstream location while-the conveyor continues to operate with the result that the packages accumulate in an upstream direction from the stop. This at times produces undesirable pressures, particularly on the article against the stop when the number of packages allowed to accumulate upstream from this point is large. A zero pressure accumulation conveyor is designed to overcome this difficulty while permitting the accumulation of containers. The zero pressure feature of an accumulation conveyor is accomplished by dividing the conveyor into a series of segments each controlled by a sensing or trigger device which by its operation brings the package to a stop before it makes contact with the next downstream article. The removel of an article in a downstream location in this type of conveyor permits each of the accumulated articles to progress one section further.

The prior art devices described above have been characterized by problems and disadvantages which desirably could be eliminated. For example, in systems wherein a single drive shaft directly drives a plurality of rollers by individual endless belts drivably interconnecting each of the rollers to the drive shaft, belt replacement has been awkward and difficult,often necessitating complete dismantling of the drive shaft.

Likewise, conventional live roller accumulation conveyors, of the zero pressure type and otherwise, have been less than satisfactory since they commonly employed components such as slip bushings and positive action brake devices to regulate power transmission to the conveyor rollers. The use of slip bushings and similar devices results in a substantial heat build up and wear when power transmission to a given group of conveyor rollers must be discontinued in order to achieve a desired accumulation or article spacing. Similarly, positive action brake devices such as, for example, arrangements wherein a stop member is interposed in the path of rotating key carried on the drive shaft, result in the transmission of suddenly applied forces through associated components which necessitates that the components of such brake devices be more substantial in construction than otherwise necessary in order to repeatedly absorb such forces over a prolonged period of use. Typically, positive action brake devices of this general type are used in conjunction with slip bushings and the like with the result that those control systems are characterized by the combined inherent problems asso-' ciated with each of these devices.

Prior art conveyors of the type generally described above are shown in numerous issued patents. For example, U.S. Pat. No. 3,124,234 (Mician), entitled Program-Controlled Automatic Casting and Maturing Field for Gas Silicate Manufacturing Plants, which describes a live roller conveyor wherein power is transmitted from a driven shaft to rollers through individual bevel gear connections. In the system of that patent the driven shaftis concentricallyspaced about the drive shaft and in segmented form with each segment having an associated positive action electromagnetic clutch associated therewith. An early patent which is generally relevant to show the state of the art to which the present invention pertains is 11.8. Pat. No. 43,387 (Blandy), entitled Steam-Engine Pump-Gearing which generally shows an idler clutch mechanism for selective transmission from a drive shaft to a driven shaft. Other patents which generally show the state of the relevant art are US. Pats. No. 896,172 (Thomas), No. 1,872,424 (Drake), No. 2,181,318 (Fessenden, Jr.), No. 3,012,652 (Poel et al.), No. 3,116,823 (Schneider), No. 3,136,406 (Good et al.), No. 3,225,893 (Currie), No. 3,255,865 (Sullivan), No. 3,266,617 (Forsyth et al.), No. 3,285,391 ,(Fix), No. 3,416,642 (Muller), No. 3,612,247 (Pipp), No. 3,621,982 (Fleischauer et al), No. 3,631,964 (Hinman et al), No. 3,643,788 (Werntz), and No. 3,650,375 (Fleischauer et.al.)

The present invention operates to overcome the foregoing problems and disadvantages by providing an improved live roller zero pressure accumulation conveyor having a plurality of axially aligned countershafts of relatively short axial extent, each of which is driven from a common drive shaft through a clutch. The rollers in this conveyor are driven by individual endless belts which are drivably connected to the axially aligned countershafts so that a given group of rollers are powered by a single countershaft. Control means for regulating power transmission to the individual groups of rollers is, in a preferred embodiment, provided by dual trigger devices associated with each group of rollers. These trigger devices cooperate to disengage the clutch for the countershaft associated with a given group of rollers when an article is held on the next downstream group of rollers to selectively control power transmission to that roller group and thereby maintain a predetermined and desired spacing between articles being conveyed. I I

It is, therefore, a general object of the present invention to provide a live roller conveyor having an improved drive system.

Another general object of the present invention is to provide an improved article spacing control system for live roller conveyors. v

Another object of the present invention is to provide a live roller accumulation conveyor of the type in which the'conveyor rollers are each driven by individual endless belts wherein belt replacement is greatly facilitated.

Another object of the present invention is to provide a live roller accumulation conveyor having a powered shaft which drives a plurality of axially aligned countershafts through individual clutches associated with each of the countershafts for selective power transmission to individual groups of conveyor rollers coupled to the countershafts by separate endless resilient belts.

Another object of the present invention is to provide an improved live roller accumulation conveyor which includes a drive shaft having a plurality of power transmitting rollers thereon, each of which drives a countershaft having a driven roller thereon, the speed of the countershaft, and correspondingly the speed of the conveyor rollers associated therewith, can be varied by the substitution therein of power transmitting rollers or driven rollers of different sizes without varying the rotational speed of the drive shaft.

Another object of the present invention is to provide an improved live roller accumulation conveyor having a plurality of roller groups which are powered by a single drive shaft operatively coupled thereto through a plurality of driven countershafts by clutches, wherein said clutches can be disengaged without incurring a heat build up and wear in the conveyor roller section powered by that countershaft as a result of the continued contact between rotating and stationary elements associated therewith.

Another object of the present invention is to provide an improved live roller accumulation conveyor wherein individual roller groups are coupled to individual driven shafts by endless belts and wherein the individual driven shafts are selectively connectable with a drive shaft through associated clutches which are equipped with brake arms that restrain continued rotation of the driven shafts when the clutches are in a disengaged (non-power transmitting) position.

Another object of the present invention is to provide an improved idler clutch for a live roller zero pressure accumulation conveyor which idler clutch has a slotted roller axis retaining arm for facilitating proper seating of the idler roller between the drive and driven rollers associated therewith.

Another object of the present invention is to provide an improved live roller zero pressure accumulation conveyor wherein power transmission to individual groups of rollers is regulated by control means which includes pairs of dual trigger devices, each pair of which is associated with one of said groups of rollers, which trigger devices cooperate to selectively regulate power transmission to the roller group with which they are associated for achieving and maintaining a desired spacing between articles being transported on the conveyor. I

Another object of the present invention is to provide an improved control means for a live roller zero pressure accumulation conveyor which can be pneumati- 6 cally or electrically actuated wherein a downstream and an upstream trigger device are associated with each group of rollers in a manner which results in LII power transmission being discontinued to a roller group located between said trigger devices when an object being transported on the conveyor actuates the downstream trigger for that group and another article is being held on the next downstream section of rollers.

These and other objects of the present invention will be apparent from the following description thereof, taken in conjunction with the accompanying drawings wherein like reference numerals have been used to designate similar components throughout and wherein:

FIG. 1 is a fragmentary perspective of a live roller accumulation conveyor embodying principles of the present invention;

FIG. 2 is a fragmentary plan view, with certain elements thereof broken away, of the live roller accumulation conveyor shown in FIG. 1;

FIG. 3 is a partial side elevational view, with portions thereof broken away, of the live roller accumulation conveyor shown in FIG. 1;

FIG. 4 is an exploded sectional view of the roller compression adjustment screw and spring assembly of the idler clutch embodiment shown in- FIG. 1;

FIG. 5 is an enlarged fragmentary perspective, with portions thereof broken away, of the idler clutch used in the embodiment of the present invention shown in FIG. 1;

FIG. 6 is a side elevational view, partially in section, of a modified idler clutch also embodying principles of the present invention;

FIG. 7 is a partial plan view, with portions thereof broken away, of the live roller accumulation conveyor shown in FIG. 1, with the countershaft separated therefrom;

FIG. 8 is a partial side elevational view, with portions thereof broken away, illustrating one of the article engaging trigger devices and associated air valve used in the control system of the present invention;

FIG. 9 is a broken sectional view of the trigger mechanism in FIG. 1 taken along the line 9-9 of that Figure;

FIG. 10 is a partial side elevational view, with portions thereof broken away, of a live roller accumulation conveyor of the present invention which incorporates a modified countershaft construction;

FIGS. 11-13 are schematic views showing in sequence, the travel of articles along a live roller conveyor apparatus having a control system embodying features of the present invention;

FIGS. 14-16 are schematic views respectively show ing the pneumatic control system embodying features of the present invention in each of the conditions depicted in FIGS. 11-13;

FIG. 17 is a schematic view showing an electrical control system also embodying features of the present invention and suitable for use in the conveyor apparatus thereof;

FIG. 18 is a partial side elevational view, with portions thereof broken away, of a live roller accumulation conveyor representing a further embodiment of the present invention;

FIG. 19 is an enlarged fragmentary elevational view, partially in section, illustrating the clutch construction of the embodiment shown in FIG. 18;

FIG. 20 is a view similar to FIG. 19 illustrating a further embodiment of the present invention;

FIG. 21 is a sectional view of the embodiment of the present invention shown in FIG. 20 taken on the line 21-21;

FIG. 22 is an enlarged fragmentary perspective, with portions thereof broken away, of a modified clutch embodying principles of the present invention;

FIG. 23 is a fragmentary top plan view of the embodiment of the present invention shown in FIG. 22 with the clutch in an engaged position; and,

FIG. 24 is a fragmentary side elevational view, partially in section, illustrating a further embodiment of the present invention.

Referring to the drawings and in particular to FIG. 1,

proved live roller zero pressure accumulation conveyor embodying features of the present invention which include a frame having sidewall members 12, 13 which rotatably support a plurality of individually powered transverse rollers 14. The upper surface of the individual rollers 14 are disposed on a common plane to define a pass line along which conveyed objects (not illustrated) are propelled in the direction indicated by the arrow 15.

A drive shaft 16 is positioned beneath the pass line and aligned in the direction of conveyor movement. In the illustrated embodiment, drive shaft 16 is of solid construction and driven by a suitable motor (not shown) operatively connected thereto in a conventional manner such as, for example, by achain and sprocket drive, direct gear coupling, or the like. Drive shaft 16 is generally continuous and supported by conventional shaft bearings 17 mounted in a plurality of spaced apart drive brackets 18 which extend downwardly from conyeyor frame cross member 19.

In accordance with one aspect of the present invention, a plurality of axially aligned countershafts 20 are provided along the length of the conveyor 11. The countershafts 20 rotate in suitable conventional bearing members 21 and 22 which are supported in cups 23 and 24 on opposite sides of drive bracket 18. Each of the countershafts 20 is driven by the drive shaft 16 through an idler clutch 25 and, in the illustrated embodiment, is provided with a plurality of slippable spools 26 corotatable therewith. If desired, as shown in FIG. and described more fully below, countershaft can alternatively be provided with integral belt grooves in place of the slippable spools 26. Poweris transferred from each spool 26 to its associated transverse roller 14 through individual 0 belts 27. The elastomeric properties of the belts 27 allow them to stretch to accommodate the spacing between rollers 14 and spools 26 as well as the 90 orientation of the driving and driven axes. The tension in belts 27 also loads the spools 26 to countershaft 20 to develop a controlled frictional torque between countershaft 20 and slippable spools 26, thereby protecting belts against overloading and consequent slippage, wear and overheating.

Replacement of O Belts 27 in the illustrated embodiment is greatly facilitated by a quick connect mouting arrangement for the countershafts 20. In particular, as is best shown in FIG. 7, each countershaft 20 is provided with opposed reduced diameter end portions 20a and 2012 which are respectively fitted within the inner races of the conventional bearing members 21 and 22 which, in turn, are respectively adapted to be received within the cups 23 and 24. In order to facilitate mounting of the countershafts 20, cup 23 has the lower arcuate portion of its flanged surface removed.

Countershaft bearings 21 and 22 are retained in the bearing support cups 23 and 24 by the initial tension elastomeric O belts 27. If replacement of a particular 0 belt is desired, however, the resiliency of the belts 27 enables them to be stretched a sufficient amount to permit bearing member 21 to be slid from the slotted bearing supporting cup 23 and bearing 22 to be rocked slightly in cup 24, all to free the countershaft for easy removal and replacement of belts. In order to insure rotation of countershaft 20 with the inner race of bearing member 22, a suitable key slot, matching hexagonal surface, or equivalent torque resistant fitting between countershaft end portion 20b and the inner race of the bearing can be provided.

As best shown in FIG. 3, only certain of the rollers 14 are, in the illustrated embodiment, individually driven by a direct O belt connection with the counter shaft spools 26 and that at certain locations, such as, the location of which overlies the idler clutch 25, the transverse roller 14a is driven by the roller 14 located immediately downstream thereof by a belt 28. As shown in FIG. 1, belt 28 is located adjacent the end of the rollers 14 opposite the end to which 0 belts 27 are connected. In this manner, the groups of rollers associated with a given countershaft are collectively controlled. For example, the group of rollers included within the bracket A of FIG. 1 are directly connected by their associated O belts to a single countershaft, likewise the group of rollers immediately upstream thereof and designated by the bracket and letter B are powered by the countershaft 20 associated therewith. Similar roller groups are provided throughout the conveyor apparatus, thereby enabling selective power transmission to each of such groups through the particular countershaft and idler clutch respectively associated therewith.

Referring to FIG. 5, drive shaft 16 is, in the illustrated embodiment, provided with a drive roller 29 which is adapted to engage with an idler roller 30 on the idler clutch 25 for transmission of power through the idler roller 30 on the countershaft roller 31. Idler clutch 25 includes an idler roller support bracket32 having integral spaced apart roller mounting arms 32a and 32b which extend upwardly from a generally planar base portion 32c. Idler roller 30 is rotatably received between mounting arms 32a, 32b for rotation about an axle 33 which is slidably fitted in an elongated slot 33a thereby permitting movement of idler roller 30 with respect to support bracket 32. In this manner idler roller v 30 is made self centering for assuring proper seating thereof with drive roller 29 and driven roller 31 when idler clutch 25 isin an engaged position. To facilitate engagement and disengagement, idler clutch 25 is pivotable about a fixed axis pin 34 which extends through each of the mounting arms 32a, 32b and is snugly fitted within an opening 18a in upstanding flange portion 18b of drive bracket 18 at one end and at theopposite end within an opening in the opposed planar surface of drive bracket 18. A pair of opposed slots 18d and 18e in mounting bracket 18 receive the ends of a plate 35 which is threaded to receive an adjusting screw 36 having a boss 36a which bears on the compresses spring 37 which has its lower end in engagement with the generally planar base portion 32c of idler clutch 25. A lock nut 38 serves to retain screw 36 in a predetermined and selected position for maintaining a desired compression in spring 37. Spring 37 biases the idler roller support bracket 32 in a clockwise direction bringing idler roller 30 into engagement with drive roller 29 and countershaft roller 31. Each of the rollers 29, 30 and 31 are constructed of suitable materials, well known to those skilled in the art, for effecting efficient power transmission by frictional means.

The idler clutch 25 of the present invention offers a number of significant advantages which heretofore have not been provided by the prior art. conveyed speed, for example, can be easily varied independently of the rotational speed of the drive shaft 16 by varying the size of the drive roller 29 and/or the countershaft roller 31. This feature would, of course, have particularly advantageous application in those conveyor installations wherein it was desired to have the rollers with a particular roller group travel at a different speed from that of the other rollers in the conveyor apparatus. The employment of the idler clutch 25 arrangement as shown and described also has the advantage of permitting selective control of torque transmitted to the countershaft 20. For example, the movement or pivoting action of the idler clutch 25 can be regulated to control the relative position or bite of the drive roller 29, idler roller 30 and countershaft roller 31. As will be readily appreciated by those skilled in this art, the nip of these respective rollers will govern the amount of torque which will be transmitted through the drive system before any slippage occurs. Likewise, the force exerted by the spring 37 can be adjusted by screw 36 to reguate the force exerted by the idler roller 30 on the drive roller 29 and countershaft roller 31 to also control the torque transmission through the drive system. It will be further appreciated that since the idler clutch 25 is inherently capable of providing slippage when a predetermined resistance to rotation is exerted on the countershaft 20, that the idler clutch itself may be used as a slip clutch for safety purposes. By the same token, the described idler clutch drive system does not preclude the additional use of a conventional slip clutch in the drive system if such is desired. For example, either I drive roller 29 or countershaft roller 31 could be of a slippage material rather than being pinned or keyed to their respective shafts. Lastly, it should also be noted that the amount of torque transmitted through this particular drive system can also be varied by using materials of a different texture which are characterized by a different coefficient of friction.

Referring to FIG. 6, a modified idler clutch 25a is shown which is generally similar to idler clutch 25 discussed above with the exception that modified idler clutch 25a incorporates an idler roller support bracket which includes a countershaft brake in the form of an integral brake arm 32d having a braking pad 32e detachably fixed thereto for facilitating replacement thereof when necessary. Braking pad 32e can be composed of any .suitable known material such as, for example, asbestos-resin compositions of the type generally used for this purpose in similar devices. When the idler clutch 25a is in the engaged position for transmis-' sion of power from drive roller 29 to countershaft roller 31 through idler roller 30, the idler roller support bracket 32 is in the position shown in phantom in FIG. 6, with the braking pad 32e out of engagement with countershaft roller 31. Correspondingly, when power transmission to countershaft 20 is discontinued via disengagement of idler clutch 24a, the pivoting of idler roller support bracket 32 about the fixed axis pin 34 brings braking pad 32e into engagement with countershaft roller 31, thereby imparting a braking action to the countershaft 20 which braking action is transmitted to the transverse rollers 14 through the spools 26 and 0 belts 27 which are associated with the countershaft 20. While in this embodiment the braking pad 32e is brought into engagement with countershaft roller 31, it will be appreciated that, if desired, braking pad 32e could be brought into direct engagement with the countershaft 20 or to an auxiliary braking surface fixed thereto.

Each of idler clutch 25 (best shown in FIG. 5) and modified idler clutch 25a (FIG. 6) is pneumatically actuated and includes a conventional diaphragm 40 and associated actuator pin 41. Diaphragm 40 is housed within a cup structure 42 and supported within a bracket 43 which depends from the base portion 18f of drive bracket 18. A high pressure air inlet fitting 44 communicates with a sealed inner chamber 45 defined by a lower housing 46 and the lower side of flexible diaphragm 40. Likewise, an atmospheric chamber 47 is defined by the opposite side of diaphragm 40 and upper housing member 48. Actuator pin 41 is seated on a reinforcing plate 49 and is adapted for free movement through opening 50 and the base portion 18f of the bracket 18 for engagement with the flat bottom surface of the base 32c of idler clutch 25 (or 25a). Opening 50 is suitably sized to not only permit free movement of actuator pin 41 but to also insure that chamber 47 is in communication with a source of atmospheric pressure. In this regard, if desired, upper housing member 48 can be provided with a suitable vent port 48a for maintaining chamber 47 at atmospheric pressure and enabling opening 50 to be sized to journal the travel of actuator pin 41. Upon actuation of pneumatic diaphragm 40, actuator pin 41 is urged upwardly against the bottom surface 32c of the base 32 of idler clutch 25 (or 25a) causing the idler roller support bracket 32 to pivot in a counterclockwise direction about the fixed axis pin 34 to disengage the idler roller 30 from drive roller 29 and countershaft roller 31. It will be recognized that other conventional means such as an electric solenoid could be used with equal effectiveness to oppose the force of spring 37 on idler clutch 25 (or 25a), thereby disengaging roller 30 from contact with rollers 29 and 31.

Article location sensing devices for selectively actuating the diaphragms 40 and thereby regulating power transmission to the individual groups of rollers is provided by a plurality of article engaging triggers 51 which are spaced along the conveyor apparatus 11 in accordance with the desired article spacing. While in the illustrated embodiment triggers 51 are shown to be in a specific configuration, it will be readily apparent that any other configuration which assures contact with the articles being conveyed along the conveyor apparatus 11 may be suitably employed. If desired, other article sensing devices such as, for example, photoelectric cells, elevated rollers, and the like may be substituted in place of the triggers 51.

Referring to FIGS. 8 and 9, article engaging triggers 51 are generally U-shaped and extend across substantially the full transverse width of the conveyor apparatus 11 and, in the illustrated embodiment, are operatively connected to air valves 52 and 53. It will be appreciated, however, that triggers generally function as signal means to initiate disengagement of idler clutch 25. Accordingly, their use is not limited to pneumatic control systems. For example, in an electrically controlled system, air valves 52 and 53 could be replaced by normally open electric switches. In the illustrated embodiment, and as will be more fully described in conjunction with FIGS. 11-16, air valve 52 communicates with air valve 530 associated with the immediate upstream trigger .via air line 54 and-air valve 53 communicates with diaphragm 40 via air line 55. Air valves 52 and 53 are actuated by valve stems 56 and 57, re-

spectively, which are in engagement with, and depressed by, leg portions 51a and 51b of U-shaped bracket 51. As shown, the terminal portions 510 and 51d are -outwardly flared and received with apertures 58a and59a permitting pivoting of the trigger about the axis defined thereby. The apertures 58a and 59a are located in mounting brackets 58 and 59 which, in turn, are mounted to frame sidewall members 12 and 13.

While the details and operation of the pneumatic valves 52 and 53 will be described more fully in connection with the discussion of FIGS. 11-16, it should be noted that, in the illustrated embodiment, conventional two-position, three-way valves have been used. However, if desired, position sensing and signal transmission in response thereto as contemplated by the present invention may be achieved through other detection and signal transmitting devices equivalent thereto which are well known to those skilled in the art.

FIG. illustrates a'modified embodiment of the present invention wherein a modified countershaft 60 is substituted in place of the countershaft and spool 26 arrangement of the previously described emboditherefrom. In connection with the discussion of the present control system for conveyor apparatus 11, it should be noted that the rollers 14 included within the discharge end station 64 can be operated and controlled in any known manner. For example, these rollers may be directly powered and regulated by a clutch and countershaft arrangement of the general type described above which is controlled by an automatic triggering device either associated with, or adjacent to, the movable stop member 65. Correspondingly, the group 64 rollers can have power transmission regulated by a switch which is manually controlled to provide for selective activation of such rollers when the articles transported by removed from the discharge station 64. If desired, rollers 14 maybe non-powered, in which event, the trigger 51): would, for control purposes, constitute the discharge end of the conveyor apparatus.

While, in the preferred embodiment of the present invention, a pneumatic control means has been illustratively set forth, it will be appreciated by those skilled in the art that alternative control systems may be used in place thereof. For example, a suitable electrical control system is described below and shown in FIG. 17. correspondingly, alternative hydraulic, mechanical, fluidic, or systems based on combinations thereof, may be used as the control means in the conveyor apparatus of the present invention.

As shown in FIGS. 14-16, the control means includesment. As shown, countershaft 60 includes a plurality of chamfered reduced diameter sections 60a around which each ofthe tensioned resilient belts 27 is driven. As such, modified countershaft 60 represents a simplified construction which can be advantageously employed in the practice of the present invention. As is true of the previously described embodiment, the rotational speed of modified countershaft60 can be varied by varying the diameter of the drive roller 29 or countershaft roller 31.

Reference is now made to FIGS. 11-15 for a description of the operation of the conveyor apparatus of the present invention. In particular, FIGS. 11-13 schematically show in sequence the transporting of three objects 61, 62 and 63 along the conveyor apparatus while FIGS. 14-16 respectively schematically illustrate the control means in each of the conditions depicted in FIGS. ll-13.

Referring to FIG. 11, it will be observed that thearticles 61, 62 and 63 on the conveyor apparatus 11 travel in the direction from right to left. In accordance with an important aspect of the present invention, the rollers 14 are respectively driven in groups which have been generally designated by the brackets labeled X, Y and Z. As previously described, the rollers 14 included with the bracket designated by the letter X are operatively connected to a-single countershaft 20x, and the rollers the group X rollers represents the discharge end station '64 which is provided-with a movablestop member 65 f at which conveyed articles are retained until removed suitable compressor and air storage tank (not shown) and furnishes a source of compressed air which typically may range from 90 psi to 100 psi. Air supply line 66 communicates respectively with the two-position three-way pneumatic valves 52, 53 and 52a through branched air lines 67, 68 and 69. When actuated, trigger 51x is adapted to engage valve stems 56 and 57 of valves 52 and 53, respectively, for selectively regulating the operation thereof.

In the condition depicted by FIGS. 11 and14, biasing springs 70 and 71 urge the valves 52 and 53 as well as the associated trigger 51x upwardly so that air inlet lines 67 and 68 respectively communicate with closed ports 72 and 73. Similarly, biasing means 74 and 75 urge pneumatic valves 52a and 53 as well as their associated trigger 51y upwardly so that air line 69 communicates with a closed port 76 in valve 52a and air line .77 communicates an atmospheric port 78 in valve 52 with a closed port 79 in valve 53a. Similarly, airline 80 communicates an atmospheric port 81 in valve 52 with the closed port of an air valve in the next upstream roller group on the conveyor apparatus. In the Figure 11 sequence, therefore, roller groups X, Y and Z are being powered and operate to convey articles 61, 62 and 63 along the conveyor 11.

In the second sequence depicted in FIGS. 12 and 15, it will be noted that the object 61 has moved downstream along the conveyor so that it has now fully depressed trigger 51.x. In accordance with the present invention, actuation of trigger 51x operates to disengage the idler clutch 25x and thereby discontinue power transmission to the rollers 14 driven by countershaft 20x and to simultaneously preset the pneumatic valve associated with the next upstream trigger 51y. As shown in schematic, FIG. 15, the depression of trigger 51x results-in valve actuating rods 56 and 57 moving their associated two-wayvalves 52 and. 53 into a second position wherein branched air line 67 now communicates with an inlet port 82 in valve 52, branched air line 68 communicates with an inlet port 83 in valve 53 and air line 77 communicates with a discharge port 84 in valve 52. Plant air is therefore discharged through port 84 via passageway 85 into air line 77 and into closed port 79 of valve 53a. Simultaneously, plant air from branched air line 68 is discharged through port 86 via passageway 97 in valve 53 and then into line 88 which communicates with the diaphragm 40x which operates to disengage the idler clutch 24x associated with the rollers 14 in group X. Power transmission to the group X rollers is thereby terminated and the object 51 remains stationary on the conveyor until it is manually or otherwise removed therefrom.

The group Y rollers, however, continue to transport package 62 along the conveyor until it engages trigger 51y as shown in FIG. 13. Referring to the associated schematic, FIG. 16, depression of trigger 51y causes valve stems 89 and 90 associated with air valves 52a and 53a, respectively, to move the valves 52a and 53a downwardly so that branched air line 69 communicates with the inlet port 91 in valve 52a and air line 77 communicates with an inlet port 92 in air valve 53a. Plant air is thereby supplied to the diaphragm 40y in the air passageway defined by air inlet line 66, branched air line 67, valve passageway 85 in valve 52, air line 77, inlet port 92, passageway 93 of valve 53a, outlet port 94 and air line 95. Upon being so activated, diaphragm 40y disengages clutch roller 25y to discontinue power transmission to the group y rollers, causing the package 62 to remain stationary on the conveyor 11. As shown in FIG. 1, air line 80 communicates with discharge port 98 in valve 52a so that plant air from lines 66 and 69 is discharged through inlet 91, passageway 98a and outlet port 98 of valve 52a into line 80 to preset an air valve at the next upstream roller group in the same manner as described above in conjunction with air line 77 and air valve 530.

Removal of the package 61 from the location thereof shown in FIGS. 12 and 13 will cause trigger 51x to return to its non-activated position via the action of biasing means 70, causing the valve 52 to return to the position shown in FIG. 14, thereby cutting off the flow of plant air into valve 53a and resulting in the diaphragm 401 being vented to the atmosphere via atmospheric port 97 in valve 53a and idler clutch 25y being biased into return engagement with its associated drive and countershaft rollers or bushings for the transmission of power to the group B conveyor rollers. Simultaneously, biasing means 71 returns air valve 53 into the position shown in FIG. 14 resulting in the cutoff of plant air to the diaphragm 40x and the venting of that diaphragm to the atmosphere through atmospheric port 96 in valve 53, enabling the idler cluch 25x associated with the group X rollers to be returned into power transmitting engagement causing the object 62 to be'transferred along the group X rollers until it engages trigger 51x and initiates a repeat of the above described cycle.

The dual spaced apart triggers described above are repeated along the conveyor apparatus 11 at intervals which correspond to the spacing desired to be achieved and maintained between articles or groups of articles which are conveyed along the conveyor 11.

Since, at the inlet end of the zero pressure accumulator conveyor apparatus, there is not controlled upstream roller section, it is only necessary that a single valve be operatively connection to the trigger (not shown) at that location. Accordingly, the diaphragm 100 associated with air valve 99 is operated and regulated in the same manner as was described above in conjunction with air valve 53a and diaphragm 40y. In particular, retention of an article at the roller section immediately downstream of the inlet roller group results in a supply of plant air into closed port 101 via air line 102 when the spring 103 biases the valve 99 in its full upward position (FIGS. 14-16). In this position, air line 104 communicates the sealed chamber of diaphragm 100 with atmospheric port 105 in valve 99. Upon depression of the trigger associated with valve 99, valve stem 106 operates to depress valve 99 so that air line 102 now communicates with inlet 107 enabling the passage of plant compressed air through passageway 108 and out of outlet port 109 into air line 104 whereupon diaphragm 100 is activated and the idler clutch associated therewith disengaged, thereby discontinuing the transmission of power to the inlet roller group.

Referring now to FIG. 17, an electrical control means is schematically illustrated which can be used in place of a pneumatic control system described above in the live roller, zero pressure, accumulation conveyor of the present invention. This electrical control means functions to provide selective power transmission to individual roller groups in substantially the same manner as was described above with respect to FIGS. 11-16. In this regard, it should be noted that .the embodiment shown in FIG. 17 is merely illustrative of one form of electrical control system which could be suitably employed in the conveyor apparatus of the present system and that various modifications could be made therefrom without departing from the present invention.

The control circuit 111 is shown to include a line switch 112 which can be manually or automatically closed to connect line 113 to any suitable power source such as, for example, a 48 volt D.C. source. At the discharge end of the conveyor apparatus, trigger 51x (FIG. 11) is adapted to close a pair of ganged switches 114 and 115 which are connected to line power via lead 116. Upon the closing of switch 114, a circuit is completed through lead 117, inductor 118, lead 119 and ground potential or return line 120. Inductor 118 and an associated core 121 comprise a solenoid which, when energized, drives the core 121 against the biasing spring 122 to pivot idler clutch 25x (FIG. 12) into a disengaged'position, discontinuing power transmission to the group X rollers.

Continued travel of the article 62 on the conveyor apparatus until it hits trigger 51y as shown in FIG. 13, results in that trigger closing a pair of ganged switches 121a, 122, thereby completing a circuit via lines 113, 116, switch 115, lines 123, 124, switch 121, line 125, inductor 125, line 127 and ground line 120. The inductor 126 and a core 128 comprise a second solenoid which, when energized, drives core 128 against biasing spring 129 to pivot the idler clutch 25y into a disengaged position, discontinuing power transmission to the group Y rollers. Since switch 122 is also closed, a circuit will be completed energizing the solenoid associated with the next upstream roller group when the trigger at the downstream end of that roller group is actuated.

'Since at the inlet end of the zero pressure accumulator conveyor apparatus of the present invention there is no controlled upstream group of rollers, it is only necessary that a single switch 130 be operatively connected to the trigger 131 which is located at the downlive roller zero pressure accumulation conveyor of the present invention having components which are either 11a generally designates a further embodiment of the V identical or closely similar to those previously described. and which accordingly, have been designated by common reference numerals. As shown, the conveyor 11a includes a countershaft 140 having a plurality of chamfered reduced diameter sections 140a around which eachiof the tensioned resilient belts 27 is driven. As in the previous embodiments, these belts operate to transfer power from the countershaft 140 to the individual transverse rollers 14. The elastomeric properties of these belts allow them to stretch to accomodate the spacing between the rollers 14 and the countershaft 140 as well as the 90 orientation of the driving and driven axes. Countershaft 140 is concentric with drive shaft 141 and supported thereon by suitable antifriction bearings 142 which permit the countershaft 140 to freely rotate on the drive shaft 141. The drive I shaft 141 is journaled in shaft bearing members 143 which are mounted to spaced apart drive brackets 144" generally similar in construction and purpose to drive brackets 18 of the previously described embodiment.

Selective power transmission from the drive shaft 141 to the driven or countershaft 140 is accomplished by means of a sliding friction clutch 145. As shown, clutch 145 includes an actuating fork or yoke 146 mounted to an ear-like extension 147 on drive bracket 144 by a pin 148. An actuating rod 146a, the movement of which can be regulated by any suitable control meanssuch as the previously described pneumatic and electrical control systems, causes actuating fork 146 to pivot about the axis of pin 148. A pair of pins 149 (only one of which is shown) extend inwardly from the upper ends of actuating fork 146 and are received within a channel 150 formed in a slidable clutch drive member 151 which is axially movable along drive shaft 141. Slidable clutch drive member 151 is mounted for corotation with drive shaft 141 by means of conventional key and slot arrangement as generally designated by the reference numeral 152. The contact surface 153 of slidable clutch'member 151 is adapted to engage with a friction disc 154 which surrounds countershaft bearing 142 and'fixedly secured toan annular countershaft support member 155. The contact surfaces 153 and 154 are composed of suitable high friction, torque transmitting materials enabling the transfer of power from the drive shaft 141 to the driven or countershaft 140. It will of course be appreciated that by selectively using materials of various textures which are character- 'ized by different coefficients of friction that sliding fric- 7 tion clutch 145 can also function'as a 'slip clutch .or

countershaft 140. Correspondingly, if desired, in certain applications, slidable clutch drive member 15 can be secured to drive shaft 141 by a high friction slip- 'pable material rather than being pinned or keyed thereto for the providing of controlled torque transmission to the countershaft 140.

FIGS. 20 and 21 illustrate a further modified con-' veyor apparatus also embodying principles of the present invention generally similar to that previously described with reference to FIGS. 18 and 19. As shown, in this embodiment the actuating fork or yoke 146 operates a sliding clutch 156 of a modified end face de- I sign from that of the sliding friction clutch 145 of FIGS. 18 and 19. In particular, clutch 156 includes a slidable clutch drive member 157, having an end face whichis provided with a series of projections 157a and detents 157b which matably engage withcomplementary projections and detents 158a and 158!) on the end face of driven clutch member 158 which is fixed to a counter shaft 159 concentric with drive shaft 141. As wasthe case with countershaft 1400f the previously described embodiment, suitable bearings 142 are provided on countershaft 159 for enabling the free rotation thereof about the drive shaft 141. As generally shown in FIG.

20, the tensioned resilient belts 27 are fitted around slippable spools 26 which can be composed of a suitable thermoplastic material such as, for example, Delrin, for providing a torque limiting coupling'which exhibits self-lubrication properties, thereby minimizing, if not totally avoiding, damage to the countershaft 159. If desired, suitable spacer sleeves 160 can be used to maintain a predetermined axial spacing between the spools 26 and the shaft 159.

' Referringto FIGS. 22 and 23, a further embodiment of the present invention is generally illustrated which drive shaft 170, similarly hournaled in suitable shaft bearings which are ot illustrated, terminates in a toothed drive gear 171 which is fixed to, and corotatable with, drive shaft by means of a key and slot arrangement as generally depicted by the reference numeral 172.

As is best shownin FIG. 23, the end portion of countershaft 173 is fitted-with a toothed gear member 174 which is co-rotatable with the driven shaft 173 by means of a suitable key or pin. A plurality of slippable spools 26 are mounted to driven shaft 173 and spaced apart by spacer sleeves 173a. As was previously described, individual 0 belts 27 transfer power from the slippable spools 27 to the transverse conveyor rollers associated therewith.

Power transmission from toothed gear drive member 171 to toothed gear driven member 174 is provided by means of a toothed clutch roll 175. As best shown in FIG. 22, the toothed clutch roll 175 is rotatably received between mounting arms 176a and 176b of a roller support bracket 176. Toothed clutch roll 175 is rotatably supported ona pin 175a which is slidably received within an elongated slot 177 for providing a selfcentering action forthe toothed clutch roll 175 when itcomes into e ngagementwith the toothed drive and v driven gears 171 and 174', respectively.

Actuation of clutch roll 165 is similar to that of idler clutch in the previously described embodiments. In particular, roller support bracket 176 is pivotable about a fixed axis pin 178 which extends through mounting arms 176a and 17612 and is snugly received within an opening 166a in upstanding flange portion 166b of drive bracket 166. A pair of opposed slots 166a and 166d in mounting bracket 166 receive the ends of a plate 179 which has a threaded opening for receiving an adjusting screw 180 having a boss (not shown) which bears on and compresses spring 181, the lower end of which is in engagement with the generally planar base portion 1760 of support bracket 176. A lock nut 182 serves to retain screw 180 in a predetermined and selected position for maintaining a desired compression on the spring 180. Spring 180 biases the toothed clutch roll 175 in a clockwise direction urging the toothed clutch roll 175 out of engagement with each of the toothed drive and driven gears 171 and 174, respectively. Toothed rollers or gears 171, 174 and 175 will.

of course, be constructed of suitable materials well known to those skilled in the art, for effecting efficient power transmission. In this regard, it is generally preferable that the toothed clutch roll 175 be composed in its entirety, or at least have a face portion, of an elastomer material exhibiting approximately the same degree of hardness as tread rubber, such as, for example, a polyurethane. Alternatively, if desired, the clutch roll may be composed of a metal with the toothed drive and driven members 171 and 174 then being composed of the elastomer material.

Referring to F IO. 24, it will be noted that the embodiment of the present invention shown therein includes a toothed or geared clutch roll 165 similar to that described above with reference to FIGS. 22 and 23. In this embodiment, however, a generally continuous drive shaft 190 is provided around which are located a plurality of axially aligned driven shafts 191 generally similar in construction to driven shaft 140 described above the reference to FIG. 18. Drive shaft 190 is journaled in bearing member 192 which, in turn, is mounted to drive bracket 193 by means of a suitable bearing cup arrangement 194. A toothed drive gear 171 is fixed for co-rotation with the drive shaft 190 by means of the key and slot arrangement 172. Correspondingly, driven or countershaft 191 is freelyrotatable about drive shaft 190 and is supported thereon at its opposite ends by suitable antifriction shaft bearings 195. Power transmission from toothed drive gear 171 through toothed clutch roll 175 is transferred to countershaft 191 by means of an annular toothed driven clutch member 197 having an outer surface which is similar in construction to driven toothed gear 174 of the embodiment shown in FIGS. 22 and 23. Annular clutch member 197 can be secured to the outer surface of countershaft 191 by means of a suitable adhesive, fastening devices or any other equivalent means. While, in the embodiment illustratedin FIG. 24, it would be noted that the resilient belts 17 are received in reduced diameter grooves 19a, it will be appreciated that suitable slippable bushings, similar to spools 26 described above, may be provided.

While, in the foregoing specification, a variety of clutch mechanisms embodying the present invention have been described in detail, it will be appreciated mission arrangements may be provided in place thereof. For example, in embodiments wherein parallel spaced apart drive and countershaft constructions are employed, similar to those shown in FIGS. 1-10, a slippable belt drive can be provided wherein a continuous belt is looped around the countershaft and drive shaft with the tension thereon being selectively controlled by a movable idler roller. Likewise, other clutch devices of types well-known in the art, such as, for example, friction clutches of various types including magnetic particle clutches and the like can be used. It will, therefore, be appreciated by those skilled in the art that modifications and variations from the above described preferred embodiments of the present invention may be made without departing from the spirit and scope of this invention. Accordingly, the present invention is limited only by the scope of the appended claims.

We claim:

1. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which acticles supported on said rollers are transported, a drive shaft, a'plurality of axially aligned individual driven shafts concentrically disposed with respect to said drive shaft, clutch means for individually and selectively connecting and disconnecting said drive shaft to said driven shaft for selective transmission of power from saiddrive shaft to said individual driven shafts, said drive shaft being connected to said individual driven shafts only when power is being transmitted from said drive shaft to said individual driven shafts, said driven shafts having an axis generally parallel to said pass line and being drivably connected to said rollers by a plurality of driven belts located along the axis of said driven shafts, whereby said drive shaft can be continuously, rotatated and in engagement with selected driven shafts to which power transmission 'is desired and engagement between said rotatingdrive shaft and selected driven shafts avoided when power transmission to said selected driven shafts is not desired.

2. A live roller conveyor apparatus as defined in claim 1 wherein said driven shafts include a plurality of grooves around which each of said resilient belts is mounted.

3. A live roller conveyor apparatus as defined in claim 1 wherein said driven shafts are provided with slip bushings around which each of said drive belts is mounted.

4. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means comprises an idler clutch having an idler roller which is selectively simultaneously engageable with said drive and driven shafts transmission of power from said drive shaft to said drive shafts.

5. A live roller conveyor apparatus as defined in claim 4 wherein said idler clutch is mounted to said frame and pivotable about a fixed axis into a first power transmitting position wherein said idler roller simultaneously engages said drive and driven shafts and a sec ond power disconnecting position wherein said idler roller is separated from at least one of said drive and driven shafts, and idler clutch including first means urging it into said first position and selectively actuated second means which moves said idler clutch into said second position.

6. A live roller conveyor apparatus as defined in claim 5 wherein said second means is pneumatically actuated.

7. A live roller conveyor apparatus as defined in claim wherein said second means is electrically actuated.

8. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means is a sliding clutch which includes a slidable clutch drive member corotatable with said drive shaft having an end face which is selectively engageable with the end face of a clutch driven member fixed to said driven shaft.

9. A live roller conveyor apparatus as defined in claim 8 wherein the end face of said slidable clutch drive member and the end face of said clutch driven member are provided with surfaces characterized by a driven end faces are in engagement with each other.

10. A live roller conveyor apparatus as defined in claim 8 wherein the end face of said slidable clutch drive member and the end face of said clutch driven member are respectively provided with a plurality of matable projections and detents for effecting the transmission of torque through said. clutch means when said clutch drive and driven end faces are in engagement with each other.

11. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means comprises a toothed clutch rollmounted to said frame and pivotable about a fixed axis into a first power transmitting position wherein said toothed clutch roll is simultaneously in engagement with complementary toothed wheels on said drive and driven shafts, said toothed clutch roll also being pivotable into a second power disconnecting position wherein it is separated from at least one of said drive and driven toothed wheels.

12. A live 'roller conveyor apparatus as defined in claim 11 wherein said toothed clutch roll has an outer surface composed of an elastomer material.

13. A live roller zero conveyor apparatus as defined in claim 11 wherein said toothed wheels on said drive and driven shafts are composed of an elastomer material.

14. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means conprises an idler clutch having an idler roller mounted to support bracket which is pivotable about a first axis to bring said idler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power receiving rollers on said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper,

' when said clutch is in a power transmitting position. 1

16. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means includes means for l drive and driven toothed wheels.

imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position.

17. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, said rollers being generally transversely aligned with respect to said pass line, a drive shaft having an axis generally parallel to said pass line, a plurality of axially aligned driven shafts generally parallel to said drive shaft, said driven shafts being independently rotatable with respect to each other, a clutch means associated with each of said driven shafts and engageable with both said drive shaft and associated driven shaft for selectively and independently connecting and disconnecting said drive shaft to the driven shaft associated with said clutch means, said rollers being drivably connected to said driven shafts by individual resilient belts, each of said driven shafts being receive within mounting supports which permit the rotation and selective remo'val'thereof, said driven shafts being retained in said mounting supports by forces exerted thereagainst by said resilient belts, whereby quick removal of said driven shafts is facilitated.

18. A liveroller conveyor apparatus as defined in claim 17 wherein said driven shafts include a plurality of grooves around which each of said resilient belts is mounted.

19. A live roller conveyor apparatus as defined in claim 17 wherein said driven shafts are provided with slip bushings around which each of said drive belts is mounted.

20. A live roller conveyor apparatus as defined in claim 17 wherein said clutch means comprises an idler clutch having an idler roller whch is selectively simultaneously engageable wth said drive and driven shafts for transmission of power from said drive shaft to said driven shafts.

21. A live roller conveyor apparatus as defined in claim 20 wherein said idler clutch is mounted to said frame and pivotable about a fixed axis into a first power transmitting position wherein said idler roller simultaneously engages said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one ofsaid drive and driven shafts, said idler clutch including first means urging it into saidfirst position and selectively actuated second means which movessaid idler clutch into said second position.

22. A live roller conveyor apparatus as defined in claim 20 wherein said second means is pneumatically actuated.

23. A live roller conveyor apparatus as defined in claim 20 wherein said second means is electrically actuated.

24. A live roller conveyor apparatus as defined in claim 17 wherein aid clutch means comprises a toothed clutch roll mounted to said frame and pivotable about a fixed axis into a first power transmitting position herein said toothed clutch roll is simultaneously in engagement with complementary toothed wheels on said sition wherein itis separated from at least one of said 25. A live roller conveyor apparatus as defined in claim 24 wherein said toothed clutch roll has an outer surface composed of an elastomer material.

26. A live roller zero conveyor apparatus as defined in claim 24 wherein said toothed wheels on said drive and driven shafts are composed of an elastomer material.

27. A live roller conveyor apparatus as defined in claim 17 wherein said clutch means comprises an idler clutch having an idler roller mounted to a support bracket which is pivotable about a first axis to bring said idler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power receiving rollers on said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers.

28. A live roller conveyor apparatus as defined in claim 27 wherein the outer surfaces of said idler, power transmitting, and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.

29. A live roller conveyor apparatus as defined in claim 17 wherein said clutch means includes means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position.

30. A live roller accumulation zero pressure conveyor apparatus comprising a frame, a plurality of rollers carried by said frame to define a pass line along which articles carried on said rollers are conveyed,said rollers being generally aligned transversely to said pass line, said drive shaft being mounted below said pass line and generally parallel thereto, a plurality of axially aligned individual driven shafts being independently mounted to said frame for independent rotation with respect to the other driven shafts axially aligned therewith, clutch means associated with each of said driven shafts, said clutch means being adapted to selectively connect and disconnect said drive shaft to the driven shaft associated therewith for selective'transmission of power from said driven shaft to said individual driven shafts, said drive shaft being connected to said individual driven shafts only when power is being transmitted from said drive shaft to said individual drive shafts, a first sensing means for detecting the presence of an article at a first location on said conveyor apparatus, a second sensing means adapted to detect the presence of an article at a second location on said conveyor apparatus upstream from said first location, a given driven shaft being drivably connected to a given group of rollers located upstream of said second location, control means operatively connected to the clutch means associated with said given driven shaft, said first and second sensing means being operatively connected to said control means and adapted to actuate the control means when objects being conveyed on said conveyor are simultaneously present at said first and second locations, whereby power to said given group of rollers will be discontinued by disengagement of said clutch means for maintaining a predetermined spacing between said articles which are transported along said pass line on said conveyor apparatus and said drive shaft can be continuously rotated and in engagement only with selected driven shafts to which power transmission is desired and engagement between said rotating drive shaft and selected driven shafts avoided when power transmission to said selected driven shafts is not desired.

31. The live roller accumulation zero pressure conveyor apparatus of claim 30 wherein said clutch means includes means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position.

32. The live roller accumulation zero pressure conveyor apparatus of claim 30 wherein each of said driven shafts is concentrically disposed around said drive shaft.

33. The live roller accumulation zero pressure conveyor apparatus of claim 30 wherein each of said driven shafts is received in mounting supports which permit the rotation and selective independent removal thereof, said driven shafts being retained in said mounting supports by forces exerted by a plurality of resilient belts which drivably connect said rollers with said driven shafts, whereby quick removal of said driven shafts is facilitated.

34. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, a drive shaft, a plurality ofaxially aligned driven shafts concentrically disposed with respect to said drive shaft, clutch means for individually and selectively transmitting power from said drive shaft to said plurality of driven shafts, said clutch means comprising an idler clutch having an idler roller mounted to a support bracket which is pivotable about a first axis to bring said idler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power receiving rollers on said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers, said driven shafts having an axis generally parallel to said pass line and being drivably connected to said rollers by a plurality of drive belts located along the axis of said driven shafts.

35. A live roller conveyor apparatus as defined in claim 34 wherein the outer surfaces of said idler, power transmitting and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.

36. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, a drive shaft, a plurality of axially aligned driven shafts concentrically disposed with respect to said drive shaft, clutch means for individually and selectively transmitting power from said driven shaft to said plurality of driven shafts, said clutch means including means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position. said driven shafts having an axis generally parallel to said pass line and being drivably connected to said rollers by a plurality of drive belts located along the axis of said driven shafts.

37. Alive roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along whicharticles supported on said rollers are transported, said rollers being generally transversely aligned with respect to said pass line, a drive shaft having an axis generally parallel to said pass line, a plurality of axially aligned driven shafts generally parallel to said drive shaft, said driven shafts being'independently rotatable with respect to each other, a clutch means associated with each of said driven shafts and engageable with both said drive shaft and associated driven shaft for selectively and independently transmitting power from said driven shaft to said associated driven shaft, said clutch means comprising an idler clutch having an idler roller mounted to'a support bracket which is pivotable about a first axis to bring said idler roller into a'first power transmitting position wherein said idler roller simultaneously engages power transmitting and power rollers on said drive and driven shafts at a second power disconnecting position wherein said idler roller is separated from at least one of said power transmittingand power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller 'to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers, and rollers being drivably connected to said driven shafts by individual resilient belts, each of said driven shafts being received within mounting supports which permit the rotation and selective removalthereof, said driven shafts being retained in said mounting supports by forces exerted thereagainst by said resilient belts, whereby quick removal of said driven shafts is facilitated.

38. A live roller conveyor apparatus as defined in claim 37 wherein the outer surfaces of said idler, power transmitting and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.

39. A live roller conveyor apparatuscomprising a frame, aplurality of rollers mounted on said frame to define'apass. line along which articles supported on said rollers are transported, said rollers being generally 22 transversely aligned with respect to said pass line, a drive shaft having an axis generally parallel to said pass line, a plurality of axially aligned driven shafts generally parallel to said drive shaft, said driven shafts being independently rotatable with respect to each other, a clutch means associated with each of said driven shafts and engageable with both said drive shaft and associated driven shaft for selectively and independently transmitting power from said drive shaft to said driven shaft, said clutch means including means for imparting a braking action to the driven shaft associated therewith when such clutch means is in a disengaged position, said rollers being drivably connected to said driven shafts by individual resilient belts, each of said driven shafts being received within mounting supports which permit rotation and selective removal thereof, said driven shafts being retained in said mounting supports by forces exerted thereagainst by said resilient belts, whereby quick removal of said driven shafts is facilitated. I

40. A live roller accumulation zero pressure conveyor apparatus comprising a frame, a plurality of rollers carried by said frame to define a pass line along which articles carried on said rollers are conveyed, said rollers being generally aligned transversely to said pass line, said drive shaft being mounted below said pass line and generally parallel thereto, a plurality of axially aligned driven shafts generally parallel to said drive shaft, each of said driven shafts being independently mounted to said frame .for independent rotation with respect to the other driven shafts axially aligned therewith, clutch means associated with each of said driven shafts, said clutch means being adapted to selectively transmit power from said drive shaft to the driven shaft associated therewith, said clutch means including means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position, a first sensing means for detecting the presence of an article at a first location on said con veyor apparatus, a second sensing means adapted to detect the presence of an article at a second location on said conveyor apparatus upstream from said first location, a given driven shaft being drivably connected to a given group of rollers located upstream of said second location, control means operatively connected to the clutch means associated with said given driven shaft, said first and second sensing means being operatively connected to said control means and adapted to actuate the control means when objects being conveyed on said conveyor are simultaneously present at said first and second locations, whereby power to said given group of rollers will be discontinued by disengagement ,of said clutch means .for maintaining a predetermined spacing between'saidarticles which are transported along said pass line on said conveyor apparatus. 

1. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which acticles supported on said rollers are transported, a drive shaft, a plurality of axially aligned individual driven shafts concentrically disposed with respect to said drive shaft, clutch means for individually and selectively connecting and disconnecting said drive shaft to said driven shaft for selective transmission of power from said drive shaft to said individual driven shafts, said drive shaft being connected to said individual driven shafts only when power is being transmitted from said drive shaft to said individual driVen shafts, said driven shafts having an axis generally parallel to said pass line and being drivably connected to said rollers by a plurality of driven belts located along the axis of said driven shafts, whereby said drive shaft can be continuously rotatated and in engagement with selected driven shafts to which power transmission is desired and engagement between said rotating drive shaft and selected driven shafts avoided when power transmission to said selected driven shafts is not desired.
 2. A live roller conveyor apparatus as defined in claim 1 wherein said driven shafts include a plurality of grooves around which each of said resilient belts is mounted.
 3. A live roller conveyor apparatus as defined in claim 1 wherein said driven shafts are provided with slip bushings around which each of said drive belts is mounted.
 4. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means comprises an idler clutch having an idler roller which is selectively simultaneously engageable with said drive and driven shafts transmission of power from said drive shaft to said drive shafts.
 5. A live roller conveyor apparatus as defined in claim 4 wherein said idler clutch is mounted to said frame and pivotable about a fixed axis into a first power transmitting position wherein said idler roller simultaneously engages said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said drive and driven shafts, and idler clutch including first means urging it into said first position and selectively actuated second means which moves said idler clutch into said second position.
 6. A live roller conveyor apparatus as defined in claim 5 wherein said second means is pneumatically actuated.
 7. A live roller conveyor apparatus as defined in claim 5 wherein said second means is electrically actuated.
 8. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means is a sliding clutch which includes a slidable clutch drive member co-rotatable with said drive shaft having an end face which is selectively engageable with the end face of a clutch driven member fixed to said driven shaft.
 9. A live roller conveyor apparatus as defined in claim 8 wherein the end face of said slidable clutch drive member and the end face of said clutch driven member are provided with surfaces characterized by a high coefficient of friction for effecting controlled transmission of torque when said clutch drive and driven end faces are in engagement with each other.
 10. A live roller conveyor apparatus as defined in claim 8 wherein the end face of said slidable clutch drive member and the end face of said clutch driven member are respectively provided with a plurality of matable projections and detents for effecting the transmission of torque through said clutch means when said clutch drive and driven end faces are in engagement with each other.
 11. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means comprises a toothed clutch roll mounted to said frame and pivotable about a fixed axis into a first power transmitting position wherein said toothed clutch roll is simultaneously in engagement with complementary toothed wheels on said drive and driven shafts, said toothed clutch roll also being pivotable into a second power disconnecting position wherein it is separated from at least one of said drive and driven toothed wheels.
 12. A live roller conveyor apparatus as defined in claim 11 wherein said toothed clutch roll has an outer surface composed of an elastomer material.
 13. A live roller zero conveyor apparatus as defined in claim 11 wherein said toothed wheels on said drive and driven shafts are composed of an elastomer material.
 14. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means conprises an idler clutch having an idler roller mounted to support bracket which is pivotable about a first axis to bring said iDler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power receiving rollers on said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers.
 15. A live roller conveyor apparatus as defined in claim 14 wherein the outer surfaces of said idler, power transmitting and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.
 16. A live roller conveyor apparatus as defined in claim 1 wherein said clutch means includes means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position.
 17. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, said rollers being generally transversely aligned with respect to said pass line, a drive shaft having an axis generally parallel to said pass line, a plurality of axially aligned driven shafts generally parallel to said drive shaft, said driven shafts being independently rotatable with respect to each other, a clutch means associated with each of said driven shafts and engageable with both said drive shaft and associated driven shaft for selectively and independently connecting and disconnecting said drive shaft to the driven shaft associated with said clutch means, said rollers being drivably connected to said driven shafts by individual resilient belts, each of said driven shafts being receive within mounting supports which permit the rotation and selective removal thereof, said driven shafts being retained in said mounting supports by forces exerted thereagainst by said resilient belts, whereby quick removal of said driven shafts is facilitated.
 18. A live roller conveyor apparatus as defined in claim 17 wherein said driven shafts include a plurality of grooves around which each of said resilient belts is mounted.
 19. A live roller conveyor apparatus as defined in claim 17 wherein said driven shafts are provided with slip bushings around which each of said drive belts is mounted.
 20. A live roller conveyor apparatus as defined in claim 17 wherein said clutch means comprises an idler clutch having an idler roller whch is selectively simultaneously engageable wth said drive and driven shafts for transmission of power from said drive shaft to said driven shafts.
 21. A live roller conveyor apparatus as defined in claim 20 wherein said idler clutch is mounted to said frame and pivotable about a fixed axis into a first power transmitting position wherein said idler roller simultaneously engages said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said drive and driven shafts, said idler clutch including first means urging it into said first position and selectively actuated second means which moves said idler clutch into said second position.
 22. A live roller conveyor apparatus as defined in claim 20 wherein said second means is pneumatically actuated.
 23. A live roller conveyor apparatus as defined in claim 20 wherein said second means is electrically actuated.
 24. A live roller conveyor apparatus as defined in claim 17 wherein aid clutch means comprises a toothed clutch roll mounted to said frame and pivotable About a fixed axis into a first power transmitting position herein said toothed clutch roll is simultaneously in engagement with complementary toothed wheels on said drive and driven shafts, said toothed clutch roll also being pivotable into a second power disconnecting position wherein it is separated from at least one of said drive and driven toothed wheels.
 25. A live roller conveyor apparatus as defined in claim 24 wherein said toothed clutch roll has an outer surface composed of an elastomer material.
 26. A live roller zero conveyor apparatus as defined in claim 24 wherein said toothed wheels on said drive and driven shafts are composed of an elastomer material.
 27. A live roller conveyor apparatus as defined in claim 17 wherein said clutch means comprises an idler clutch having an idler roller mounted to a support bracket which is pivotable about a first axis to bring said idler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power receiving rollers on said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers.
 28. A live roller conveyor apparatus as defined in claim 27 wherein the outer surfaces of said idler, power transmitting, and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.
 29. A live roller conveyor apparatus as defined in claim 17 wherein said clutch means includes means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position.
 30. A live roller accumulation zero pressure conveyor apparatus comprising a frame, a plurality of rollers carried by said frame to define a pass line along which articles carried on said rollers are conveyed, said rollers being generally aligned transversely to said pass line, said drive shaft being mounted below said pass line and generally parallel thereto, a plurality of axially aligned individual driven shafts being independently mounted to said frame for independent rotation with respect to the other driven shafts axially aligned therewith, clutch means associated with each of said driven shafts, said clutch means being adapted to selectively connect and disconnect said drive shaft to the driven shaft associated therewith for selective transmission of power from said driven shaft to said individual driven shafts, said drive shaft being connected to said individual driven shafts only when power is being transmitted from said drive shaft to said individual drive shafts, a first sensing means for detecting the presence of an article at a first location on said conveyor apparatus, a second sensing means adapted to detect the presence of an article at a second location on said conveyor apparatus upstream from said first location, a given driven shaft being drivably connected to a given group of rollers located upstream of said second location, control means operatively connected to the clutch means associated with said given driven shaft, said first and second sensing means being operatively connected to said control means and adapted to actuate the control means when objects being conveyed on said conveyor are simultaneously present at said first and second locations, whereby power to said given group of rollers will be discontinued by disengagement of said clutch means for maintaining a predetermined spaCing between said articles which are transported along said pass line on said conveyor apparatus and said drive shaft can be continuously rotated and in engagement only with selected driven shafts to which power transmission is desired and engagement between said rotating drive shaft and selected driven shafts avoided when power transmission to said selected driven shafts is not desired.
 31. The live roller accumulation zero pressure conveyor apparatus of claim 30 wherein said clutch means includes means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position.
 32. The live roller accumulation zero pressure conveyor apparatus of claim 30 wherein each of said driven shafts is concentrically disposed around said drive shaft.
 33. The live roller accumulation zero pressure conveyor apparatus of claim 30 wherein each of said driven shafts is received in mounting supports which permit the rotation and selective independent removal thereof, said driven shafts being retained in said mounting supports by forces exerted by a plurality of resilient belts which drivably connect said rollers with said driven shafts, whereby quick removal of said driven shafts is facilitated.
 34. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, a drive shaft, a plurality of axially aligned driven shafts concentrically disposed with respect to said drive shaft, clutch means for individually and selectively transmitting power from said drive shaft to said plurality of driven shafts, said clutch means comprising an idler clutch having an idler roller mounted to a support bracket which is pivotable about a first axis to bring said idler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power receiving rollers on said drive and driven shafts and a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers, said driven shafts having an axis generally parallel to said pass line and being drivably connected to said rollers by a plurality of drive belts located along the axis of said driven shafts.
 35. A live roller conveyor apparatus as defined in claim 34 wherein the outer surfaces of said idler, power transmitting and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.
 36. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, a drive shaft, a plurality of axially aligned driven shafts concentrically disposed with respect to said drive shaft, clutch means for individually and selectively transmitting power from said driven shaft to said plurality of driven shafts, said clutch means including means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position, said driven shafts having an axis generally parallel to said pass line and being drivably connected to said rollers by a plurality of drive belts located along the axis of said driven shafts.
 37. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, said rollers being generally transversely aligned with respect to said pass line, a drive shaft having an axis generally parallel to said pass line, a plurality of axially aligned driven shafts generally parallel to said drive shaft, said driven shafts being independently rotatable with respect to each other, a clutch means associated with each of said driven shafts and engageable with both said drive shaft and associated driven shaft for selectively and independently transmitting power from said driven shaft to said associated driven shaft, said clutch means comprising an idler clutch having an idler roller mounted to a support bracket which is pivotable about a first axis to bring said idler roller into a first power transmitting position wherein said idler roller simultaneously engages power transmitting and power rollers on said drive and driven shafts at a second power disconnecting position wherein said idler roller is separated from at least one of said power transmitting and power receiving rollers, said idler roller including a centrally disposed and outwardly extending axle which is received within elongated slots in said support bracket, whereby the axle of said idler roller is adapted to slide in said elongated slots to provide movement of said idler roller with respect to said support bracket enabling said idler roller to be self-centering for facilitating the proper seating thereof with said power transmitting and power receiving rollers, and rollers being drivably connected to said driven shafts by individual resilient belts, each of said driven shafts being received within mounting supports which permit the rotation and selective removal thereof, said driven shafts being retained in said mounting supports by forces exerted thereagainst by said resilient belts, whereby quick removal of said driven shafts is facilitated.
 38. A live roller conveyor apparatus as defined in claim 37 wherein the outer surfaces of said idler, power transmitting and power receiving rollers are provided with teeth which are adapted to be in mesh engagement when said clutch is in a power transmitting position.
 39. A live roller conveyor apparatus comprising a frame, a plurality of rollers mounted on said frame to define a pass line along which articles supported on said rollers are transported, said rollers being generally transversely aligned with respect to said pass line, a drive shaft having an axis generally parallel to said pass line, a plurality of axially aligned driven shafts generally parallel to said drive shaft, said driven shafts being independently rotatable with respect to each other, a clutch means associated with each of said driven shafts and engageable with both said drive shaft and associated driven shaft for selectively and independently transmitting power from said drive shaft to said driven shaft, said clutch means including means for imparting a braking action to the driven shaft associated therewith when such clutch means is in a disengaged position, said rollers being drivably connected to said driven shafts by individual resilient belts, each of said driven shafts being received within mounting supports which permit rotation and selective removal thereof, said driven shafts being retained in said mounting supports by forces exerted thereagainst by said resilient belts, whereby quick removal of said driven shafts is facilitated.
 40. A live roller accumulation zero pressure conveyor apparatus comprising a frame, a plurality of rollers carried by said frame to define a pass line along which articles carried on said rollers are conveyed, said rollers being generally aligned transversely to said pass line, said drive shaft being mounted below said pass line and generally parallel thereto, a plurality of axially aligned driven shafts generally parallel to said drive shaft, each of said driven shafts being independently mounted to said frame for independent rotation with respect to the other driven shafts axially aligned therewith, clutch Means associated with each of said driven shafts, said clutch means being adapted to selectively transmit power from said drive shaft to the driven shaft associated therewith, said clutch means including means for imparting a braking action to the driven shaft associated therewith when said clutch means is in a disengaged position, a first sensing means for detecting the presence of an article at a first location on said conveyor apparatus, a second sensing means adapted to detect the presence of an article at a second location on said conveyor apparatus upstream from said first location, a given driven shaft being drivably connected to a given group of rollers located upstream of said second location, control means operatively connected to the clutch means associated with said given driven shaft, said first and second sensing means being operatively connected to said control means and adapted to actuate the control means when objects being conveyed on said conveyor are simultaneously present at said first and second locations, whereby power to said given group of rollers will be discontinued by disengagement of said clutch means for maintaining a predetermined spacing between said articles which are transported along said pass line on said conveyor apparatus. 